A heat recovery device comprises a valve body inwardly defining a direct flow path for exhaust gases from an inlet to an outlet, a heat exchanger comprising a flow passage for the exhaust gases emerging in an inlet zone of the valve body, and a gate positioned in the valve body. The heat recovery device comprises a guide wall positioned in the direct flow path at the inlet zone, arranged to guide the exhaust gases from the inlet toward the cutoff section away from the inlet zone when the gate frees the direct flow path, and delimiting at least one orifice to allow the exhaust gases to go to the inlet zone when the gate closes off the direct flow path.